Brownie Layer

Cup of Yum
1. Preheat oven to 350 degrees F. Line bottom of a 9" springform pan with parchment paper and spray paper and sides of pan with cooking spray (I use a baking spray, but you could use regular spray and lightly dust with flour instead).
2. In a small saucepan, melt butter and chocolate until smooth, over low heat, stirring often.
3. Turn off heat and whisk in sugar. Set aside to cool for 5-10 minutes, stirring often.
4. To a mixing bowl, add in melted chocolate mixture, milk and eggs, whisking quickly so the residual heat doesn't cook the eggs.
5. Use a wooden spoon to stir in flour until just combined. Pour batter into prepared pan in an even layer, and bake for 25 minutes.

Cheesecake Layer

1. Remove brownie pan from the oven and set aside.
2. Reduce oven temperature to 325 degrees F.
3. Using a stand mixer (or hand mixer), beat all cheesecake ingredients together until mixture is smooth. Take care not to mix too quickly, or air bubbles will form.
4. Pour cheesecake batter over brownie layer in pan.
5. Bake for 50 minutes, until center is slightly jiggly (or when an instant read thermometer inserted into the center reads 150.
6. Remove from oven and cool at room temperature, with the pan on a wire rack for 30 minutes to 1 hour.
7. Place pan in the refrigerator for 4 hours, or overnight to chill and firm up to that amazing cheesecake consistency.

Cookie Dough Layer

1. In a stand mixer (or hand mixer), cream together butter and both sugars on MED-HIGH speed until light and fluffy.
2. Beat in sweetened condensed milk and vanilla extract.
3. Beat in salt and flour. Stir in mini chocolate chips.
4. Use an offset spatula to gently spread cookie dough over the top of the cooled cheesecake.
5. This is done most easily when the spring has been undone and the cheesecake is free from the sides of the pan.
6. If you can't spread the cookie dough, gently press pieces together to "spackle" the cookie dough onto the cheesecake.

Finish the Cheesecake

1. Microwave milk chocolate chips and vegetable oil in 30 second bursts (stirring each time), until nearly melted. Stir to melt remaining lumps.
2. Drizzle melted chocolate over the top of the cheesecake.
3. To slice, use a long, thin knife. Dip knife blade into very hot water, shake off excess and slice carefully. Between each slice, use a paper towel to wipe off cake crumbs and reside, then dip knife into the hot water again before slicing.